This invention relates to a sewage treatment system. More particularly the invention relates to a system which purifies sewage effluent to an extent which permits the purified effluent to be used for a variety of purposes and even renders the effluent potable.
In those areas which do not have a public sewage system, it is common for residences, commercial establishments or other buildings to have individual sewage treatment systems. Each of these systems generally comprises a septic tank having different compartments in which the solid waste is broken apart and dissolved to a partially purified fluid by the interaction of the aerobic/anaerobic bacteria balance. Additionally, the scum and grease which collects on top of the fluid is attacked and partly decomposed by aerobic microorganisms which are present in the septic tank in a relatively small amount. Suitable means are provided to permit the treated effluent to flow by force of gravity from the septic tank into a drainage field or directly into a river or stream.
However, since conventional septic tanks do not have an adequate aerobic/anaerobic bacteria balance, the treated sewage still contains significant amounts of coliform while having a high biological oxygen demand. As such the effluent is a major source of pollution of the lakes, streams and subsurface waters. In turn, the effluent can be a health hazard to a community as well as being a hazard to the environment and ecology.
Generally, conventional sewage systems of the type under discussion require suitable drainage means to function properly. When a system is installed in the ground which has poor percolation it is extremely difficult to obtain adequate drainage of the treated effluent. The results of this can cause not only great inconvenience to the people using the system but also can pose a significant health problem.
The pollution and health hazards associated with conventional septic systems can be attributed to the fact that the effluent is either discharged directly into a stream or drained into a subsurface drainage field which normally is so far below the land surface as to prevent further natural bacteriological treatment of the effluent. In such systems the effluent is considered useless waste. The present invention not only solves the pollution and health problems of the conventional sewage systems but also provides an effluent which has a variety of uses such as for irrigation and is even potable.